Is pressure relief design necessary for pipelines transporting oil products?

If the pipeline is used intermittently and has valves at both ends, it can be in a closed state; moreover, in areas with high temperatures during summer, a pressure relief design should be in place to prevent overpressure caused by the rise in temperature of the oil.

In accordance with the \"SH3007-1999 Code for Design of Tank Areas in Petrochemical Storage and Transportation Systems\", \"4.4.17 Pipelines carrying Class A and Class B liquids shall be equipped with pressure relief measures.\" ”Do it according to the regulations. For your reference.

There should be pressure relief facilities, and our tank area’s pipelines all have them.

Pipelines used for transporting oil certainly need to take pressure relief into consideration. When the external temperature rises, the pressure inside the pipeline increases as well (due to the thermal expansion property of the pipeline material). In such cases, if there are no pressure relief points, the fluid inside the pipeline will seek a weak spot to release pressure. The opposite occurs when the external temperature drops; therefore, pipelines for transporting oil definitely need to address the issue of pressure relief. The pressure relief design of pipelines is primarily determined based on the properties of the medium being transported.

Thank you all for your guidance. I have another question: for heavy crude oil pipelines that are transported with heat tracing, is it also necessary to consider pressure relief design?

What you’re referring to is actually the issue related to the installation of the oil expansion tube or pressure relief tube. It generally has a diameter of DN40; one end is connected to the pipeline near the oil tank, and the other end is connected to the tank top. A stop valve and a safety valve are installed on the pipe, or sometimes a stop valve and a check valve are used as well. Normally, the stop valve is kept open, and it is closed during oil collection operations.

There are pressure relief facilities, and they are available on all the pipelines in my oil tank area.

We generally also use the method from floor 7

If liquefied hydrocarbon pipelines are exposed to direct sunlight, pressure relief measures for the pipelines should be considered.

This issue highlights the differences between design work at home and abroad. There are no regulations abroad that mandate the installation of expansion relief measures, but owners will ask the design firm to make a decision based on the actual calculations for the project. If the pipe expansion pressure is within the design pressure range, it is not necessary to install it ； If it exceeds the limit, additional installation is required.

Our facility originally had stop valves and safety valves installed on its gasoline pipelines; we now want to carry out modifications. Are there any better solutions?

The issue of safe pressure relief should be considered.

If pressure relief is a concern, then a pressure relief valve should be installed between the pipelines for every two valves that could be misoperated. As a result, the investment will be very large. So, what I do is basically install expansion relief valves only on large, long pipelines. As mentioned above, it is decided whether to install it based on a comparison between the expansion pressure and the design pressure, but in practice, such a comparison is very difficult to carry out accurately. Hehe, it’s because the coefficient of expansion, volume, and other factors are all related.

Due to reasons such as safety and accidental operations, a pressure relief device is necessary

The original post was posted by hcbbszy on 2007-12-28 at 17:00. If pressure relief is a concern, then a pressure relief valve should be installed between the pipelines for every two valves that could be misused. As a result, the investment will be very large. So, what I do is basically install expansion relief valves only on large, long pipelines. As mentioned above, it depends on the comparison between the expansion pressure and the design pressure to determine whether… [/quote] Due to the incompressibility of liquids, when a pipe with both ends sealed is filled with liquid, any increase in temperature – such as from sunlight or heating – results in equal-volume expansion. For every 1-degree rise in temperature, the pressure increases sharply. I can’t recall the exact calculations from chemical thermodynamics, but I think the increase is extremely high; the consequences usually include internal leakage in the valves and flanges, and in some cases, pipe rupture. Therefore, under no circumstances should pressure not be relieved due to cost or operational reasons. Even for short pipes, as long as they are not in continuous operation or it’s possible to empty part of them, proper design is necessary – absolutely essential! As for pipes connecting multiple valves, it’s possible to arrange for some of the valves to remain open at all times; otherwise, the valves will also experience internal leakage

Regardless of the type of pipeline, as long as temperature and volume changes result in corresponding pressure changes, pressure relief devices must be installed.